Despite the hundreds of pilot studies using mobile health-also known as 'mHealth'', which describe medical and public health practice supported by mobile devices- there is insufficient evidence to inform the widespread implementation and scale-up of this technology, according to international researchers writing in this week's PLOS Medicine.

There are over 6 billion mobile phone subscribers and 75% of the world has access to a mobile phone leading health care providers, researchers, and national governments to be optimistic about the opportunities mobile health has to offer. However, the authors led by Mark Tomlinson from Stellenbosch University in South Africa, question the evidence supporting the scale up of mHealth.

The authors say: "In some ways, mobile technology has a magical appeal for those interested in global public health over and above the advantages that have been proven with good evidence."

They continue: "Part of this magical promise is that mobile technologies may solve one of the most difficult problems facing global health efforts-that of structural barriers to access."

However, according to the authors while enthusiasm for effective mHealth interventions in sub-Saharan Africa is high, little is known about their efficacy or effectiveness.

They say: "The current wave of mHealth interventions are the equivalent of black boxes. Each small entrepreneur or researcher includes whatever bells and whistles that their funding allows in an attempt to demonstrate efficacy."

The authors argue that potential innovative research designs such as multi-factorial strategies, randomized controlled trials, and data farming may provide this evidence base and make several recommendations for the way forward.

The authors also argue that major donors could invest in creating a robust set of standards and a platform that can inform and support local adaptation of mHealth applications. The standardized features of the platform could then be available to all local technicians committed to improving the health of their local communities.

The authors conclude: "We also believe a global strategy for programmatic examination of the optimal features of the mobile platforms is needed." Tomlinson M, Rotheram-Borus MJ, Swartz L, Tsai AC (2013) Scaling Up mHealth: Where Is the Evidence? PLoS Med 10(2): e1001382. doi:10.1371/journal.pmed.100138